I have recently had some problems understanding the new poison and the regeneration penalty on burning, would anyone care to explain them to me?

I understand how burning stacks (for purposes of damage) works, and I had no problem with the old poison either. I just feel there is some untapped potential in there, since I havent completely understood to use them yet.

"Which farm animal is featured prominently in Desktop Dungeons?" "Snakes"

Burning lowers regen by the listed amount, so extends the life of poison (since poison just "blocks" a specific amount of total health regen).

Best way to use them both is to make sure you're able to burn the enemy before you go revealing black space. The Whaargarbl is really nice with poison strategies since your autoattacks won't drop the burning stacks.

Burning is pretty complex. The glyph itself only tells you that it slows regenration (not by how much, however). The additional damage per stack only gets mentioned by the Whurgarbl buff. That is actually pretty weird... perhaps we need a puzzle for Burndayraz.